CN109136571B

CN109136571B - Method for extracting valuable metals from lithium ion battery mixed manganese-rich waste leachate

Info

Publication number: CN109136571B
Application number: CN201811136233.9A
Authority: CN
Inventors: 杨越; 孙伟; 宋绍乐; 胡岳华
Original assignee: Central South University
Current assignee: Essokai Recycling Energy Technology Guangxi Co ltd
Priority date: 2018-09-28
Filing date: 2018-09-28
Publication date: 2020-04-07
Anticipated expiration: 2038-09-28
Also published as: CN109136571A

Abstract

本发明公开了一种从锂离子电池混合富锰废料浸出液中高效分离有价金属的方法。首先，采用沉淀法从富锰溶液中选择性沉淀分离镍钴组分；然后，借助氨与钴、镍，沉淀剂与钴、镍络合成键作用的差异，采用氨与铵盐的混合溶液，选择性的溶解镍钴沉淀渣中的镍组分，实现镍和钴的高效分离；最后，利用溶剂萃取法选择性的提取沉淀镍钴后溶液中的锰组分，实现锰与锂的高效分离。本发明提出的“选择性沉淀镍钴‑余液锰锂萃取分离‑沉淀渣中镍选择性溶取并镍钴分离”工艺，可以规避传统萃取法从高锰溶液中分离镍钴流程长、效果差的缺点，操作简单，流程短，成本低，可实现废旧锂离子电池富锰浸出液中有价组分元素的高效分离与回收。The invention discloses a method for efficiently separating valuable metals from the mixed manganese-rich waste leaching solution of lithium ion batteries. First, the nickel and cobalt components were selectively precipitated and separated from the manganese-rich solution by the precipitation method; then, with the help of the difference in the complex bonds between ammonia and cobalt and nickel, the precipitant, cobalt and nickel, the mixed solution of ammonia and ammonium salt was used. , selectively dissolve the nickel components in the nickel-cobalt precipitation residue to achieve efficient separation of nickel and cobalt; finally, the solvent extraction method is used to selectively extract the manganese components in the solution after precipitating nickel-cobalt to achieve high efficiency of manganese and lithium. separation. The process of "selective precipitation of nickel and cobalt-extraction and separation of manganese and lithium in residual liquid-selective extraction of nickel from precipitation residue and separation of nickel and cobalt" proposed by the present invention can avoid the traditional extraction method for separating nickel and cobalt from high manganese solution, which has a long process and good effect. The disadvantage is that the operation is simple, the process is short, and the cost is low, which can realize the efficient separation and recovery of valuable component elements in the manganese-rich leaching solution of waste lithium-ion batteries.

Description

Method for extracting valuable metals from lithium ion battery mixed manganese-rich waste leachate

Technical Field

The invention relates to the field of waste battery recovery, in particular to a method for extracting valuable metals from a lithium ion battery mixed manganese-rich waste leachate.

Technical Field

With the development and progress of human society, the consumption of energy is more and more. However, the continuous consumption of fossil energy not only causes the resource to be exhausted increasingly, but also brings about serious environmental problems. In order to relieve the dependence on fossil energy and protect the environment, the development of new energy automobile industry is greatly promoted in various countries. The lithium ion battery is one of important power supplies of new energy automobiles, and the production scale of the lithium ion battery is continuously enlarged. However, the service life of a power lithium ion battery is generally 3-5 years, and a large number of lithium ion batteries must generate a large number of waste lithium ion batteries. In the lithium ion batteries, valuable resources such as nickel, cobalt, manganese, iron, aluminum, copper, lithium and the like are contained, and if the valuable resources cannot be effectively recycled, the environment is polluted, and the resources are wasted, so that economic loss is caused.

At present, the waste lithium ion battery recovered in China mainly adopts a wet process, and the recovery process design mainly aims at waste lithium cobaltate and ternary materials. The waste lithium ion battery is discharged, disassembled, crushed and physically sorted. Then, the obtained positive active substance is leached in acid to make nickel, cobalt, manganese and lithium enter into the solution. And finally, fine adjusting the proportion of the components of the solution by an element separation method or by adding nickel sulfate, cobalt sulfate or manganese sulfate to form a mother solution for preparing the precursor of the lithium battery anode material in a regeneration mode. However, with the continuous development of new energy automobile industry, the demand of lithium ion battery cathode materials is increasing, but with the consumption and price increase of cobalt resources, the proportion of ternary materials and lithium manganate mixed materials in the power battery material market is increasing, and the ternary materials and lithium manganate mixed materials are successfully applied to electric automobiles such as solar elevation (Leaf), united states general volta (Volt) and the like. On the one hand, the cost of the material can be reduced by mixing; on the other hand, the lithium manganate has more stable structure and good safety, and the safety of the ternary material can be improved by mixing. However, the blending of power lithium ion battery materials presents new challenges to lithium ion battery recycling. With the increase of the manganese content in the material, the traditional P204 extraction manganese-P507 nickel-cobalt separation process has large manganese extraction capacity and can cause the loss of nickel-cobalt. Meanwhile, due to the low nickel and cobalt content, the subsequent nickel and cobalt separation process is long, and the separation efficiency is low. If the method of adjusting the structure of the solution is adopted, a large amount of nickel sulfate and cobalt sulfate needs to be supplemented. Therefore, the efficient separation and extraction of elements such as nickel, cobalt and the like from the high-manganese leaching solution is a difficult problem in the treatment of the mixed manganese-rich waste of the lithium ion battery, and a more efficient valuable component separation and recovery process needs to be developed urgently.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a method for efficiently separating valuable metal components from waste lithium ion battery materials, in particular to a method for extracting the valuable metal components from a lithium ion battery mixed manganese-rich waste leachate.

The invention relates to a method for extracting valuable metals from a lithium ion battery mixed manganese-rich waste leachate, which comprises the steps of separating nickel and cobalt from manganese and lithium in the manganese-rich waste leachate by adopting a precipitation method to obtain nickel-cobalt-containing slag and a liquid phase containing manganese and lithium, separating and recycling nickel and cobalt in the nickel-cobalt-containing slag, and separating and recycling the liquid phase containing manganese and lithium.

According to the method for extracting valuable metals from the lithium ion battery mixed manganese-rich waste leachate, a specific mode that a precipitation method is adopted to separate nickel and cobalt from manganese and lithium in the manganese-rich waste leachate is that a precipitator is added into the manganese-rich waste leachate, the manganese-rich waste leachate is stirred and reacted for 1-3 hours at the temperature of 20-70 ℃, the pH value is controlled to be 2-6 during the reaction, and the stirring speed is controlled to be 100-300 r/min.

As a further preferable mode, the precipitant is selected from any one of xanthic acid, sodium xanthate, thiram sodium, thiram manganese and thiuram. The addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 2: 1-7: 1.

as a further preference, when the precipitant is selected from xanthic acid or sodium xanthate, the precipitant is added in a molar ratio of: (nickel + cobalt) ═ 2: 1-4: 1; controlling the pH value to be 4.5-5.5 during reaction;

when the precipitant is selected from sodium feromethione, the addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 3:1 to 4: 1; controlling the pH value to be 3-6 during reaction;

when the precipitant is selected from manganese dimethyl dithiocarbamate, the addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 5: 1-7: 1; controlling the pH value to be 3-6 during the reaction.

The inventor finds that the pH value has great influence on the nickel-cobalt precipitation rate and the manganese loss rate in the precipitation process, the dosage of the precipitator is prepared according to the preferable scheme aiming at different precipitants, the pH value is controlled, the nickel-cobalt precipitation can be efficiently realized, and the manganese and cobalt loss can be avoided.

As a preferred scheme, the method for extracting valuable metals from the lithium ion battery mixed manganese-rich waste leachate comprises the steps of carrying out nickel selective leaching on nickel-containing and cobalt-containing residues by adopting a mixed solution of ammonia water and ammonium salt, and carrying out solid-liquid separation to obtain a nickel-containing liquid phase and cobalt-containing residues; the molar ratio of the ammonia water to the ammonium salt is 2-4: 1, and the concentration of the ammonia water is 2-6 mol/L.

As a further preferable scheme, the liquid-solid volume mass ratio of the mixed solution of the ammonia water and the ammonium salt to the slag containing nickel and cobalt is 5-10 ml: 1g of the total weight of the composition.

The ammonium salt is selected from any one of ammonium chloride, ammonium sulfate, ammonium bisulfate and ammonium sulfide.

As a further preferable scheme, the leaching temperature during leaching is 20-60 ℃, the leaching time is 0.5-3 h, and the stirring speed during leaching is 100-300 r/min.

The inventor finds that the slag containing nickel and cobalt obtained by the precipitation method can be used for separating nickel and cobalt by one-step leaching of a mixed solution of ammonia water and ammonium salt, and the preferred precipitator has stronger binding capacity with the cobalt than that of the nickel and the precipitator, and simultaneously the nickel and the NH₄ ⁺Complexing power of cobalt to NH₄ ⁺So that nickel will complex with NH during the leaching process of the present invention₄ ⁺A complex compound which is dissolved in water is formed, and cobalt is hardly dissolved, namely, the separation of nickel and cobalt is effectively realized.

Preferably, the method for extracting valuable metals from the lithium ion battery mixed manganese-rich waste leachate comprises the step of separating manganese and lithium in a liquid phase containing manganese and lithium by an extraction method to obtain a manganese-containing organic liquid phase and a lithium-containing liquid phase, wherein an extracting agent used in the extraction is selected from P204 (di (2-ethylhexyl) phosphate) or P507 (ethylhexyl phosphoric acid mono-2-ethylhexyl ester), and the pH value of the manganese-containing liquid phase and the lithium-containing liquid phase is controlled to be 2-6.

Preferably, when the extracting agent used in the extraction is P204, the pH of the manganese-lithium-containing liquid phase is controlled to be 2-4; and when the extracting agent used in the extraction is P507, the pH of the liquid phase containing manganese and lithium is controlled to be 4-6.

As a further preferred scheme, the diluent used for extraction is sulfonated kerosene; the volume fraction of the extracting agent in the extracted organic phase is 40-60%, and during extraction, the volume ratio of the extracted organic phase to the aqueous phase is 1-2: 1.

as a further preferable scheme, the extraction time is 5-15 minutes, and the extraction temperature is 20-40 ℃.

As a further preferable scheme, back extraction is carried out on the obtained manganese-containing organic liquid phase by adopting a sulfuric acid solution to obtain a manganese sulfate solution, wherein the concentration of the sulfuric acid solution is 1-2 mol/L.

In a further preferred embodiment, the volume ratio of the extracted organic phase to the aqueous phase in the stripping is 0.5: 1-2: 1, the back extraction time is 10-20 minutes, and the back extraction temperature is 25-50 ℃.

As a preferred scheme, the method for extracting valuable metals from a lithium ion battery mixed manganese-rich waste leachate is characterized in that the manganese-rich waste leachate is a sulfuric acid leachate of a waste lithium ion battery anode material, the mass concentration of manganese in the manganese-rich waste leachate is 25-100 g/L, and the manganese in the manganese-rich waste leachate is as follows by mass ratio: (nickel + cobalt) 1-20.

As a further preferred scheme, the anode material of the waste lithium ion battery is LiNi_xCo_yMn_1-x-yO₂(x,y<1)、LiCoO₂With LiMn₂O₃A mixture of components.

The principle and the advantages of the invention are as follows:

the invention provides a targeted valuable metal extraction process aiming at a manganese-rich waste leachate for the first time, and the extraction and separation of nickel and cobalt are realized by adopting selective precipitation to recover nickel and cobalt with low content and then selectively dissolving nickel from precipitation slag through a backwashing process. And finally, separating manganese and lithium by adopting an extraction process, thereby realizing comprehensive and efficient recovery of all elements of nickel, cobalt, manganese and lithium in the waste lithium ion battery material.

According to the invention, a precipitation method is adopted to selectively precipitate and recover nickel and cobalt with low content from the manganese-rich waste leachate, the amount of the precipitated slag is small, the problem that nickel and cobalt are easily lost in the manganese extraction process of the traditional process can be avoided, and the treatment efficiency is high.

Because the physical and chemical properties of nickel and cobalt elements are similar, the traditional extraction method has long process and poor effect for separating nickel and cobalt. The invention skillfully adopts the mixed solution of ammonia water and ammonium salt to selectively dissolve nickel in the nickel-containing and cobalt-containing slag formed by the precipitation process, and efficiently and simply realizes the separation of nickel and cobalt.

In conclusion, the invention realizes the full component recovery of nickel, cobalt, manganese and lithium resources and has high recovery rate by the process of selective precipitation of nickel and cobalt, extraction and separation of manganese and lithium in residual solution, and selective dissolution and nickel and cobalt separation of nickel in the precipitation slag. The targeted treatment process for the manganese-rich waste liquid has great application significance and value under the condition of increasingly mixing the power lithium ion battery materials at present.

Drawings

FIG. 1 is a graph of nickel cobalt precipitation rate versus pH for example 1.

FIG. 2 is a graph showing the relationship between the leaching rate of nickel and the concentration of aqueous ammonia in example 1.

Detailed Description

The present invention will be described in detail with reference to specific embodiments.

Example 1

Taking 100ml LiMn₂O₃And LiNi_1/3Co_1/3Mn_1/3O₂The sulfuric acid leach solution of the mixed materials was placed in a 250ml round bottom flask, and the contents of nickel, cobalt, manganese and lithium in the solution are shown in table 1. Putting the round-bottom flask into a water bath kettle at 50 ℃ for heating, adding sodium xanthate into the solution, and controlling the molar ratio of the sodium ethylxanthate to the nickel cobalt in the solution to be 2.3: 1, under the condition of magnetic stirring at 150 revolutions per minute, reacting for 2 hours. In the reaction process, the pH value is a very key action factor, and the relationship between the nickel-cobalt precipitation rate and the pH valueAs shown in fig. 1. The precipitation rate of nickel and cobalt increases with increasing pH, but when the pH exceeds 5, the loss rate of manganese in the solution becomes significantly high, and the pH is controlled to 5 for effective control of the manganese content in the precipitate. After the reaction was completed and filtered, the contents of nickel, cobalt, manganese, and lithium in the solution were measured by ICP, and the nickel precipitation rate was calculated to be 95.25%, and the cobalt precipitation rate was calculated to be 99.81%. The loss rate of manganese is less than 8 percent, and the loss rate of lithium is 2.28 percent.

10g of the precipitate was taken out and placed in 60ml of an aqueous ammonia solution to react at room temperature and 25 ℃ for 1 hour. The relationship between the leaching rate of nickel and the concentration of ammonia water is shown in FIG. 2. The leaching rate of nickel is increased and then reduced along with the increase of the concentration of ammonia water, and when the concentration of ammonia water is too high, the pH value in the solution is too high, so that nickel and cobalt are precipitated by hydroxide. Therefore, the ammonia concentration in the solution is selected to be 4mol/L for leaching, and the primary leaching rate of nickel is only 30 percent. This is because only the active free radical of ammonia [ NH ]₃]Can be mixed with Ni²⁺A water-soluble complex is formed, and the ammonia water is hydrolyzed to form NH₄ ⁺Losing the complexing ability. To ensure complexing power in solution [ NH ]₃]Concentration, additional NH addition is required₄ ⁺Promoting reactive free radicals [ NH ]₃]And (4) generating. The experimental result shows that on the premise that other reaction conditions are not changed, when the adding amount of ammonium chloride is controlled to be 1mol after the ammonium chloride is added into the solution, the leaching rate of nickel is improved to more than 98%, cobalt is hardly dissolved, and nickel and cobalt are selectively separated.

20ml of sodium xanthate is taken to precipitate, remove nickel and cobalt and then filtrate obtained by filtration is placed in a 150ml separating funnel. Dissolving di (2-ethylhexyl) phosphate serving as an extracting agent into sulfonated kerosene according to the volume ratio of 1:1, measuring 20ml of dissolved extracting agent solution, and adding the extracting agent solution into filtrate with the same volume. The mixture was extracted by shaking on a shaker at 25 ℃ for 10 minutes. The pH value of the solution is adjusted, when the pH value of the solution is low, the extraction rate of manganese is insufficient, when the pH value of the solution is high, manganese can be extracted by 100%, but part of lithium and manganese enter an organic phase together. Thus, the pH was controlled at about 3.5 by selecting the median value. After the extraction is finished and the oil phase is separated by standing, the metal content in the solution is measured, and the result shows that the extraction rate of manganese reaches 100 percent and the extraction rate of lithium is less than 5 percent.

Table 1 content of valuable metals in manganese-rich leach liquor of example 1

Nickel concentration (g/L)	Cobalt concentration (g/L)	Manganese concentration (g/L)	Lithium concentration (g/L)
				4.067	4.084	46.974	4.466

Example 2

The leaching solution used in this example is the same as example 1, the precipitant for separating nickel and cobalt is ethyl xanthic acid, the reaction steps and conditions are the same as example 1, the results are similar and are not repeated, 10g of precipitate is taken and placed in 60ml of mixed solution of 4mol/L ammonia water and 0.5mol/L ammonium sulfate, and the reaction is carried out for 1 hour at room temperature of 25 ℃. The leaching rate of nickel is more than 98 percent, and cobalt is not dissolved.

20ml of sodium xanthate is taken to precipitate, remove nickel and cobalt and then filtrate obtained by filtration is placed in a 150ml separating funnel. Dissolving ethylhexyl phosphoric acid mono-2-ethylhexyl ester serving as an extracting agent into sulfonated kerosene according to the volume ratio of 1:1, measuring 20ml of dissolved extracting agent solution, and adding the extracting agent solution into filtrate with the same volume. The mixture was extracted by shaking on a shaker at 25 ℃ for 10 minutes. The manganese and lithium extraction rates are related to the pH as shown in table 2. The results show that when the pH value is about 5, lithium is not basically extracted, and the extraction rate of manganese reaches 100%.

TABLE 2 manganese and lithium extraction vs. pH in example 2

pH value	2	3	4	5
					Lithium ion source	-	10	50	>99
Manganese oxide	-	0.3	0.5	0.8

Example 3

The leachate used in this example was the same as in example 1. The precipitant for separating nickel and cobalt is sodium ferometalate, the reaction steps and reaction conditions are basically similar to those of examples 1 and 2, except that the relation between the addition amount of the precipitant sodium ferometalate and the content of nickel and cobalt is as follows: the molar ratio of the used amount of the sodium fermet to the nickel cobalt is 3.5: 1. The pH value was controlled at 5.0, and the results showed that the precipitation rates of nickel and cobalt were both 99% or more.

The process of manganese-lithium separation and nickel-cobalt separation in this example is the same as the steps and conditions of example 1, and the effects of nickel-cobalt separation and manganese-lithium separation are also substantially the same as those of example 1.

Example 4

The leachate used in this example was the same as in example 3. The precipitator for separating nickel and cobalt is manganese dimethyl ether, the reaction steps and reaction conditions are the same as those of the embodiment 3, the difference is that the relation between the addition amount of the precipitator manganese dimethyl ether and the content of the nickel and cobalt is as follows: the molar ratio of the used amount of the manganese fumarate to the nickel cobalt is 6: 1. The pH value was controlled at 4.5, and the results showed that the precipitation rates of nickel and cobalt were both 98.5% or more.

The process of manganese-lithium separation and nickel-cobalt separation in this example is the same as the steps and conditions of example 2, and the effects of nickel-cobalt separation and manganese-lithium separation are also substantially the same as example 2.

Example 5

LiMn is selected in this example₂O₃，LiCoO₂And LiNi_1/3Co_1/3Mn_1/3O₂The leaching solution of the mixed material comprises 2.01g/L of Ni,8.12g/L of Co,38g/L of Mn and 5.01g/L of Li. The content of sodium xanthate in the solution was controlled to 60g/L, and other conditions were the same as in example 1. The precipitation rate of nickel and cobalt can reach 99%, the loss rate of manganese is lower than 8%, and the loss rate of lithium is lower than 3%.

The conditions and procedures for nickel-cobalt separation and manganese-lithium separation were the same as in example 1, and the results were substantially the same.

Comparative example 1

The leachate used in this example was the same as in example 1. A process for extracting and separating nickel and cobalt by precipitation and demanganization-P507 by hydroxide precipitation. Adding ammonia water into the solution, controlling the ammonia concentration to be 2mol/L, adjusting the pH value of the solution to be 9, reacting for 2 hours, wherein the removal rate of manganese in the solution is less than 90%, and the loss rate of nickel and cobalt is more than 20%. When nickel and cobalt are extracted and separated subsequently, the pH value is 4.5, and the oil phase is 1:1, the volume concentration of the extractant is 40 percent, the extraction time is 8 minutes, and after 4-stage countercurrent extraction, nickel and cobalt are completely separated, but manganese can enter a cobalt product. Therefore, the metal extraction process is very complicated due to the existence of a large amount of manganese in the high-manganese waste ion battery.

Comparative example 2

The leachate and nickel cobalt precipitation selected in this example were the same as in example 1. The difference is that the pH value in the precipitation process is 3.5, the precipitation rate of cobalt is 99 percent, the precipitation rate of nickel is only 82 percent, and the recovery rate of nickel is insufficient.

Comparative example 3

The conditions for leaching and nickel cobalt precipitation were exactly the same as in example 2. After obtaining the nickel cobalt precipitate, the conditions for separating nickel and cobalt from the precipitate were the same as in example 1, except that the separation temperature was 60 ℃, the concentration of ammonia capable of complexing with nickel in the solution was reduced due to the more volatile ammonia content at elevated temperature, and the leaching rate of nickel was less than 15% and could not be separated from cobalt.

Comparative example 4

The leachate used in this example was the same as in example 1. Sulfidation is used to precipitate nickel and cobalt from solution. Taking 100ml LiMn₂O₃And LiNi_1/3Co_1/3Mn_1/3O₂Placing the sulfuric acid leaching solution of the mixed material into a 250ml round bottom flask, and adding Na with 2.4 times of theoretical amount required for precipitating nickel and cobalt into the solution at 60 DEG C₂And S, controlling the pH value to be 3.5, reacting for 2.5 hours, wherein the precipitation rate of nickel and cobalt reaches 99 percent. The nickel-cobalt precipitate was treated under exactly the same conditions and in exactly the same manner as in example 1, and neither nickel nor cobalt was dissolved and could not be separated.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention relates, several equivalents and obvious modifications may be made without departing from the spirit of the invention and are deemed to be within the scope of the invention.

Claims

1. A method for extracting valuable metals from a lithium ion battery mixed manganese-rich waste leachate is characterized by comprising the following steps: adding a precipitant into a manganese-rich waste leachate, stirring and reacting at 20-70 ℃ for 1-3 hours, controlling the pH to be 2-6 during the reaction, controlling the stirring speed to be 100-300 r/min, obtaining nickel-containing cobalt slag and a liquid phase containing manganese and lithium, wherein the precipitant is selected from any one of xanthic acid, sodium xanthate, sodium thiram, manganese thiram and thiuram, selectively leaching nickel from the nickel-containing cobalt slag by adopting a mixed solution of ammonia water and ammonium salt, and performing solid-liquid separation to obtain a nickel-containing liquid phase and a cobalt-containing slag; and separating and recovering the liquid phase containing manganese and lithium.

2. The method for extracting valuable metals from the mixed manganese-rich waste leachate of the lithium ion battery according to claim 1, wherein the method comprises the following steps: the addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 2:1 to 7: 1.

3. The method for extracting valuable metals from the lithium ion battery mixed manganese-rich waste leachate according to claim 2, wherein the method comprises the following steps: when the precipitant is selected from xanthic acid or sodium xanthate, the addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 2: 1-4: 1; controlling the pH value to be 4.5-5.5 during reaction;

when the precipitant is selected from sodium feromethione, the addition amount of the precipitant is as follows according to molar ratio: (nickel + cobalt) ═ 2: 1-4: 1; controlling the pH value to be 3-6 during reaction;

4. The method for extracting valuable metals from the mixed manganese-rich waste leachate of the lithium ion battery according to claim 1, wherein the method comprises the following steps: the molar ratio of the ammonia water to the ammonium salt is 2-4: 1, and the concentration of the ammonia water is 2-6 mol/L.

5. The method for extracting valuable metals from the leachate of the mixed manganese-rich waste of the lithium ion battery as claimed in claim 1 or 4, wherein: the volume-to-solid mass ratio of the mixed solution of the ammonia water and the ammonium salt to the nickel-containing cobalt slag is 5-10 ml: 1g of a compound; the ammonium salt is selected from any one of ammonium chloride, ammonium sulfate, ammonium bisulfate and ammonium sulfide; the leaching temperature during leaching is 20-60 ℃, the leaching time is 0.5-1 h, and the stirring speed during leaching is 100-300 r/min.

6. The method for extracting valuable metals from the mixed manganese-rich waste leachate of the lithium ion battery according to claim 1, wherein the method comprises the following steps: separating manganese and lithium in a liquid phase containing manganese and lithium by adopting an extraction method to obtain a manganese-containing organic liquid phase and a lithium-containing liquid phase, wherein an extracting agent used in the extraction is selected from P204 or P507, and the pH value of the manganese-containing liquid phase and the lithium-containing liquid phase is controlled to be 2-6.

7. The method of claim 6, wherein the method comprises the steps of: when the extracting agent used in the extraction is P204, the pH value of the liquid phase containing manganese and lithium is controlled to be 2-4;

when the extracting agent used in the extraction is P507, the pH value of the liquid phase containing manganese and lithium is controlled to be 4-6;

the diluent used for extraction is sulfonated kerosene; the volume fraction of the extracting agent in the extracted organic phase is 40-60%, and during extraction, the volume ratio of the extracted organic phase to the aqueous phase is 1-2: 1;

the extraction time is 5-15 minutes, and the extraction temperature is 20-40 ℃.

8. The method of claim 6, wherein the method comprises the steps of: carrying out back extraction on the obtained manganese-containing organic liquid phase by adopting a sulfuric acid solution to obtain a manganese sulfate solution, wherein the concentration of the sulfuric acid solution is 1-2 mol/L;

in the back extraction, the volume ratio of the extracted organic phase to the aqueous phase is 0.5: 1-2: 1, the back extraction time is 10-20 minutes, and the back extraction temperature is 25-50 ℃.

9. According to the claimsThe method for extracting valuable metals from the lithium ion battery mixed manganese-rich waste leachate in claim 1 is characterized by comprising the following steps of: the manganese-rich waste leachate is a sulfuric acid leachate of a waste lithium ion battery anode material, the mass concentration of manganese in the manganese-rich waste leachate is 25-100 g/L, and in the manganese-rich waste leachate, the mass ratio of manganese: (nickel + cobalt) 1-20; the anode material of the waste lithium ion battery is LiNi_xCo_yMn_1-x-yO₂(x,y<1)、LiCoO₂With LiMn₂O₃A mixture of components.